Visual ecology and potassium conductances of insect photoreceptors.
(2016) In Journal of Neurophysiology 115(4). p.2147-2157- Abstract
- Voltage-activated potassium channels (Kv channels) in the microvillar photoreceptors of arthropods are responsible for repolarization and regulation of photoreceptor signaling bandwidth. On the basis of analyzing Kv channels in dipteran flies, it was suggested that diurnal, rapidly flying insects predominantly express sustained K+ conductances, whereas crepuscular and nocturnally active animals exhibit strongly inactivating Kv conductances. The latter was suggested to function for minimizing cellular energy consumption. In this study we further explore the evolutionary adaptations of the photoreceptor channelome to visual ecology and behavior by comparing K+ conductances in 15 phylogenetically diverse insects, using patch-clamp recordings... (More)
- Voltage-activated potassium channels (Kv channels) in the microvillar photoreceptors of arthropods are responsible for repolarization and regulation of photoreceptor signaling bandwidth. On the basis of analyzing Kv channels in dipteran flies, it was suggested that diurnal, rapidly flying insects predominantly express sustained K+ conductances, whereas crepuscular and nocturnally active animals exhibit strongly inactivating Kv conductances. The latter was suggested to function for minimizing cellular energy consumption. In this study we further explore the evolutionary adaptations of the photoreceptor channelome to visual ecology and behavior by comparing K+ conductances in 15 phylogenetically diverse insects, using patch-clamp recordings from dissociated ommatidia. We show that rapid diurnal flyers such as the blowfly (Calliphora vicina) and the honeybee (Apis mellifera) express relatively large noninactivating Kv conductances, conforming to the earlier hypothesis in Diptera. Nocturnal and/or slow-moving species do not in general exhibit stronger Kv conductance inactivation in the physiological membrane voltage range, but the photoreceptors in species that are known to rely more on vision behaviorally had higher densities of sustained Kv conductances than photoreceptors of less visually guided species. No statistically significant trends related to visual performance could be identified for the rapidly inactivating Kv conductances. Counterintuitively, strong negative correlations were observed between photoreceptor capacitance and specific membrane conductance for both sustained and inactivating fractions of Kv conductance, suggesting insignificant evolutionary pressure to offset negative effects of high capacitance on membrane filtering with increased conductance. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/1b02e879-41a5-4cd0-99a2-8efc8c0a4125
- author
- Frolov, Roman ; Immonen, Esa-Ville LU and Weckström, Matti
- publishing date
- 2016-04-01
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- insect photoreceptor, potassium channels, compund eye, visual ecology
- in
- Journal of Neurophysiology
- volume
- 115
- issue
- 4
- pages
- 2147 - 2157
- publisher
- American Physiological Society
- external identifiers
-
- pmid:26864762
- scopus:84984646187
- ISSN
- 1522-1598
- DOI
- 10.1152/jn.00795.2015
- language
- English
- LU publication?
- no
- id
- 1b02e879-41a5-4cd0-99a2-8efc8c0a4125
- date added to LUP
- 2016-07-04 10:50:47
- date last changed
- 2022-03-16 07:00:39
@article{1b02e879-41a5-4cd0-99a2-8efc8c0a4125,
abstract = {{Voltage-activated potassium channels (Kv channels) in the microvillar photoreceptors of arthropods are responsible for repolarization and regulation of photoreceptor signaling bandwidth. On the basis of analyzing Kv channels in dipteran flies, it was suggested that diurnal, rapidly flying insects predominantly express sustained K+ conductances, whereas crepuscular and nocturnally active animals exhibit strongly inactivating Kv conductances. The latter was suggested to function for minimizing cellular energy consumption. In this study we further explore the evolutionary adaptations of the photoreceptor channelome to visual ecology and behavior by comparing K+ conductances in 15 phylogenetically diverse insects, using patch-clamp recordings from dissociated ommatidia. We show that rapid diurnal flyers such as the blowfly (Calliphora vicina) and the honeybee (Apis mellifera) express relatively large noninactivating Kv conductances, conforming to the earlier hypothesis in Diptera. Nocturnal and/or slow-moving species do not in general exhibit stronger Kv conductance inactivation in the physiological membrane voltage range, but the photoreceptors in species that are known to rely more on vision behaviorally had higher densities of sustained Kv conductances than photoreceptors of less visually guided species. No statistically significant trends related to visual performance could be identified for the rapidly inactivating Kv conductances. Counterintuitively, strong negative correlations were observed between photoreceptor capacitance and specific membrane conductance for both sustained and inactivating fractions of Kv conductance, suggesting insignificant evolutionary pressure to offset negative effects of high capacitance on membrane filtering with increased conductance.}},
author = {{Frolov, Roman and Immonen, Esa-Ville and Weckström, Matti}},
issn = {{1522-1598}},
keywords = {{insect photoreceptor; potassium channels; compund eye; visual ecology}},
language = {{eng}},
month = {{04}},
number = {{4}},
pages = {{2147--2157}},
publisher = {{American Physiological Society}},
series = {{Journal of Neurophysiology}},
title = {{Visual ecology and potassium conductances of insect photoreceptors.}},
url = {{http://dx.doi.org/10.1152/jn.00795.2015}},
doi = {{10.1152/jn.00795.2015}},
volume = {{115}},
year = {{2016}},
}